I've watched the new episode twice now, and I gotta say, the mystery is great.
Since I saw the trailer, I thought the idea of not following the Reds and Blues, and instead focussing on new characters, investigating, was interesting. I'm glad to see it working. This first episode has quite a chilling vibe, and really leaves me hungry for more.
As for speculation, I don't know if I'm sold on the AI fragments taking over, especially since Church takes off his helmet. I'd be fairly confident in saying it isn't them acting of their accord (or being manipulated) either, because of Sarge's weapon choice and Caboose setting up a bomb. To me this only really leaves them being copycats, perhaps even from the UNSC, set up to justify an invasion of Chorus.
Also, personally, I'd love to see Locus return, maybe even tracking down the Reds and Blues himself, possibly joining our journalist friends. Although, if he doesn't, I won't be too dissapointed.